why can't I use "that" here

English grammar questions, answered by Alan

Moderator: Alan

Posts: 2
Joined: Tue Oct 25, 2016 9:07 am
Status: Learner of English

why can't I use "that" here

Post by BOTEGUO » Sat Aug 04, 2018 10:03 am

A computer is so useful a machine ______ we can use everywhere.

The text book answer key, according to the teacher from my school, is "which" , which makes it an attributive clause. So why can't I use "that" instead of "which" in this sentence since in most of the attributive clause one can be replaced by the other?

I know that in certain circumstances we can only use "that" or "which", but to my knowledge this ain't one of them. Help me out here, please.

Thanks for your time and help.

User avatar
Posts: 13028
Joined: Mon Dec 29, 2003 7:56 pm
Status: Teacher of English

Re: why can't I use "that" here

Post by Alan » Thu Aug 09, 2018 4:52 am

In fact the sentence, as written, is highly unnatural with either.

Are you certain you have copied it correctly?

However, for what it is worth, 'that' as relative pronoun would certainly be as acceptable as 'which'.